On December 31, 2015, the 20-year-old WBO strawweight world champion, Kosei Tanaka (5-0, 2 KOs), faced a 25-year-old Filipino boxer Vic Saludar (11-1, 9 KOs), in a title defense fight.
Tanaka came in to the fight on a 5-fight win streak with a 40% KO rate, and was fighting after a gap of 7 months and 1 day. Saludar was on a 9-fight win streak with a 75% KO rate, and fighting after a layoff of 3 months and 22 days.
Kosei Tanaka stopped Vic Saludar via KO in the 6th round of the 12-round world-title fight, and successfully defended his WBO strawweight title. Tanaka improves his record to 6-0 (3 KOs), while Saludar adds a loss to his record at 11-2.
On December 31, 2019, the 24-year-old WBO flyweight world champion, Kosei Tanaka (14-0, 8 KOs), faced Wulan Tuolehazi, in a title defense fight.
Tanaka came in to the fight on a 14-fight win streak with a 57% KO rate, and was fighting after a gap of 4 months and 7 days.
Kosei Tanaka made easy work of Wulan Tuolehazi, stopping the challenger via KO in the 3rd. Tanaka improves his record to 15-0 (9 KOs)
On August 24, 2019, the 24-year-old WBO flyweight world champion, Kosei Tanaka (13-0, 7 KOs), faced a 28-year-old Puerto Rican boxer Jonathan González (22-2-1, 13 KOs), in a title defense fight.
Tanaka came in to the fight on a 13-fight win streak with a 53% KO rate, and was fighting after a gap of 5 months and 8 days. González was on a 4-fight win streak with a 52% KO rate, and fighting after a layoff of 9 months and 8 days.
Kosei Tanaka stopped Jonathan González via TKO in the 7th round of the 12-round world-title fight, and successfully defended his WBO flyweight title. Tanaka improves his record to 14-0 (8 KOs), while González adds a loss to his record at 22-3-1.
On December 31, 2016, 21-year-old Kosei Tanaka (7-0, 4 KOs) and Moisés Fuentes fought for the vacant WBO light-flyweight title.
Tanaka came in to the fight on a 7-fight win streak with a 57% KO rate, and was fighting after a gap of 7 months and 3 days.
Kosei Tanaka stopped Moisés Fuentes via TKO in the 5th round of the 12-round world-title fight. Tanaka improves his record to 8-0 (5 KOs)
On September 13, 2017, the 22-year-old WBO light-flyweight world champion, Kosei Tanaka (9-0, 5 KOs), faced Palangpol CP Freshmart, in a title defense fight.
Tanaka came in to the fight on a 9-fight win streak with a 55% KO rate, and was fighting after a gap of 3 months and 24 days.
Kosei Tanaka stopped Palangpol CP Freshmart via TKO in the 9th round of the 12-round world-title fight, and successfully defended his WBO light-flyweight title. Tanaka improves his record to 10-0 (6 KOs)
On May 20, 2017, the 21-year-old WBO light-flyweight world champion, Kosei Tanaka (8-0, 5 KOs), faced a 26-year-old Puerto Rican boxer Ángel Acosta (16-0, 16 KOs), in a title defense fight.
Tanaka came in to the fight on a 8-fight win streak with a 62% KO rate, and was fighting after a gap of 4 months and 20 days. Acosta was on a 16-fight win streak with a 100% KO rate, and fighting after a layoff of 3 months and 9 days.
Kosei Tanaka defeated Ángel Acosta via unanimous decision and successfully defended his WBO light-flyweight title. Tanaka improves his record to 9-0, while Acosta adds a loss to his record at 16-1.
On March 16, 2019, the 23-year-old WBO flyweight world champion, Kosei Tanaka (12-0, 7 KOs), faced a 32-year-old fellow Japanese boxer Ryoichi Taguchi (27-3-2, 12 KOs), in a title defense fight.
Tanaka came in to the fight on a 12-fight win streak with a 58% KO rate, and was fighting after a gap of 5 months and 20 days. Taguchi was on a -1-fight win streak with a 37% KO rate, and fighting after a layoff of 9 months and 24 days.
Kosei Tanaka defeated Ryoichi Taguchi via unanimous decision and successfully defended his WBO flyweight title. Tanaka improves his record to 13-0, while Taguchi adds a loss to his record at 27-4-2.
On February 24, 2024, 28-year-old Kosei Tanaka (19-1, 11 KOs) and Christian Bacasegua Rangel fought for the vacant WBO super-flyweight title.
Tanaka came in to the fight on a 4-fight win streak with a 55% KO rate, and was fighting after a gap of 9 months and 3 days.
Kosei Tanaka defeated Christian Bacasegua Rangel via unanimous decision . Tanaka improves his record to 20-1
On May 30, 2015, 19-year-old Kosei Tanaka (4-0, 2 KOs) and Julian Yedras fought for the vacant WBO strawweight title.
Tanaka came in to the fight on a 4-fight win streak with a 50% KO rate, and was fighting after a gap of 7 months.
Kosei Tanaka defeated Julian Yedras via unanimous decision . Tanaka improves his record to 5-0
On September 24, 2018, a 23-year-old Kosei Tanaka (11-0, 7 KOs) got a shot at the WBO flyweight title held by Sho Kimura.
Tanaka came in to the fight on a 11-fight win streak with a 63% KO rate, and was fighting after a gap of 5 months and 24 days.
Kosei Tanaka defeated Sho Kimura via majority decision and wins the WBO title. Tanaka improves his record to 12-0